Rotating gas drilling head



Jan. 10, 1967, c. R. DALE I ROTATING GAS DRILLING HEAD Original FiledJune '7, 1965 .FGo 1' "1 2 Sheets-Sheet 1 m mm A m N l w 1 m m3 r Jan.10, 1967 c. R. DALE 3,297,091

ROTATING GAS DRILLING HEAD Original Filed June 7, 1963 2 Sheets-Sheet 2INVENTOR.

CL .QQENCE R. D91. 5

United States Patent 3,297,091 ROTATING GAS DRILLING HEAD Ciarence R.Dale, 121 Real Road, Bakersfield, Caiif. 93309 Continuation of abandonedapplication Ser. No. 286,352, June 7, 1963. This application June 30,1965, Ser. No. 470,332

14!- Clairns. (Cl. 166-84) The present application is a continuation ofmy application Serial Number 286,352, filed June 7, 1963 on Rotating GasDrilling Head and now abandoned.

This invention has to do generally with improvements in casing headassemblies especially adapted for use in the drilling of wells by theuse of air or other gases (all of which are intended to be inclusive inthe term gas) which is maintained under circulation down through thedrill string to a bit or other cutting tool, for return flow withentrained cuttings to the ground surface.

More particularly, the invention is directed to a novel head structuredesigned with the objectives of maintaining very simple and effectively,seals against consequential leakage about the drill string ofpressurized gas introduced to the well and casing, and further to thepractical end that by reason of its simple structure and serviceability,the drilling head may be manufactured and maintained at exceptionallylow costs.

Gas drilling is practiced using a drill string having a top polygonal orkelly section rotatable as by a conven tional table positioned above thecasing head assembly. The present invention contemplates maintenance ofa gas scape seal about the kelly, and in a manner significantlydiffering from conventional practices of attempting seal maintenances bythe use of contractive but otherwise relatively stationary packers aboutthe drill string or kelly. Such conventional packing heads are found toperform less efficiently and to involve far greater expense than thepresent simplified form of head.

Structurally, the invention contemplates a gas drilling head comprisinga body positionable about the kelly above the casing as between a rotarytable and blowout preventer, the drilling head body containing a packingassembly having a kelly-passing opening, and characterized in therespects of being both rotatable by the kelly, and displaceable by thecasing gas pressure longitudinally thereof, to constitute in effect afloating unit which maintains seals against both the kelly and wall ofthe body. The packing assembly is further characterized as beingapplicable to and removable from the kelly by virtue of split orsectional construction as later described.

In particular reference to the packing assembly, the invention has forits object to provide a metallic holder apertured in accordance with thecross sectional configuration of the kelly, and carrying correspondinglyoriented packing which engages and seals about the kelly. The holderalso mounts packing which engages against the inside wall of the headbody to maintain a second annular seal. As will appear, the packingassembly has such exposure to the casing gas pressure, as to bedisplaceable upwardly thereby in the head, the displacement range beingpredetermined by spaced stop shoulders or surfaces against which theassembly is rotatable. By reason of the consequent pressure floatationgiven the packing assembly during operation, all functional and sealingsurfaces in the head are relieved of any loads or pressures that couldresult in excessive wear. As a consequence, the head is capable of longservice without necessary or expensive replacements or repairs.

Further objects of the invention have to do more particularly withcertain details of the packing assembly construction. As to thesefeatures, the invention contemplates split formation of the packingholder for lateral 3,297,691 ?atented Jan. it], 1967 ICC application toand removal from the kelly, and its design in a manner capable ofaccommodating sectional or split' annular packing segments in the insideand about the kelly, as well as similarly formed packing segments at theoutside adjacent the body wall. In this manner it is made possible toemploy packing of readily available and inexpensive form and materials,which can be easily assembled and replaced.

Serviceability of the head is further enhanced by the provision of meansfor introducing lubricant to the head at one or more locations assuringlubrication of friction surfaces against which the packing rotates.

The invention further contemplates accommodation about the kelly of apacking assembly as previously characterized, in a manner capable ofremoval to permit with drawal from the well of larger size tools orbits, where an outer body containing the seal is adequately sized topass the tools, but may be oversized beyond requirements of the sealassembly, or of a smaller or more standard seal and body assembly usablewith smaller tools. Generally, the invention contemplates adapteraccommodation of a smaller seal body within an outer enlarged body orshell, so that the former may be removed for tool passage through theouter body.

All the various features and objects of the invention, as well as thedetails of illustrative embodiments thereof, will be more fullyunderstood from the following detailed description of the accompanyingdrawings in which:

FIG. 1 is a diagrammatic showing of the drilling head in a typicalassociation with a rotary table and blowout preventer;

FIG. 2 is a plan view of the drilling head as taken;

FIG. 3 is a view showing the drilling head in vertical section, buttaken in the broken plane 3-3 of FIG. 5 to show one of the outer packingadjustment screws;

FIGS. 4 and 5 are reduced scale cross sections taken respectively onlines 44 and 5-5 of FIG. 3; and

FIG. 6 is a view similar to FIG. 3 showing a variational form of theinvention.

FIG. 1 is illustrative of a typical arrangement for air drilling,according to which the tubular drill string carrying at its lower end adrill bit, is run down through the casing 10. The drill string includesthe usual top kelly section ill whereby the string is rotated by theusual rotary table 12 having bushings 13 which pass and engage thepolygonal cross section kelly. The invention is concerned with thedrilling head generally indicated at 14 shown to be positioned above andconnected by nipple 15 with a blow-out preventer 16 which may be of anyappropriate type. During drilling pressurized gas is discharged downthrough drill string and bit to entrain cuttings which are carriedupwardly through the casing and blow-out preventer to be discharged at17. As previously indicated, the general function of the head 14- is tomaintain during drilling a rotating seal against escape of gas whichordinarily may be pressurized within the casing upwardly of p.s.i.

Referring now to FIG. 3, the head 14 shown to comprise a tubular body 13to which, if desired, may be applied an annular jacket 19 forcirculation therethrough, from an inlet 20 to an outlet 21, of coolingfluid for dissipation of heat from the body, created internally bypacking rotation against the inner surface 22 of the body seal. Thelatter is shown to contain a bottom welded ring 23 flush with the top ofnipple 15 to present at 24 a supporting surface for the internal packingassembly generally indicated at 25. Suitable provision may be made forsupplying lubricant to and along the internal body surface 22 tominimize frictional resistance to packing rotation, as by way of hose orline 26 through which lubricant from a constant supply sourcediagrammatically indicated at 27, is delivered into the head so as tocompletely film the body surface 22 by virtue of the packing assemblyrotation and its vertical displacement.

The packing assembly 25 is shown to comprise a metallic holder 28 formedin diametrically split sections 28a, see FIG. 4, applicable laterallyabout the kelly Ill and releasably held together by upper and lowerpairs 23 and 30 of screws 31 set into counterbores 32 in section 28a. Asviewed in FIG. 3, the holder 28 has an internal recess in the form of acounterbore 33, an outer recess vertically defined by holder 34 andangular or wedge holder 35, and the bottom recess between surfaces 36and 37. It will be observed that the bottom of the packing assembly 25is exposed to the casing or nipple gas pressure, allowing for upwarddisplacement of the assembly, as will later appear. Below thecounterbore 33, the holder 28 has a polygonal or essentially squareopening 38 in conformance with the cross sectional configuration of thekelly so that during drilling, the kelly rotation is imparted to theholder 28 and therefore to the packing assembly.

Recess 33 contains suitable packing, generally indicated at 39, forengaging and sealing about the kelly, the packing advantageously, thoughtypically, being in the form of radially spit rings of belting 48alternating with correspondingly split neoprene rings 41. These packingrings, preferably formed with a single split at 42 (although if desiredthey may be diametrically split), may be applied laterally about thekelly, and by reason of their split configurations, are adapted for easyreplacement or inspection. As shown in FIG. 5, the packing 39, like theholder 28, has a square configuration at 43 in conformance with thekelly. The packing assembly 39 is compressible longitudinally of andagainst the kelly by a ring 44 which in turn is thrust downwardly byscrews 4s threaded through the ring 45 and carrying retaining nuts 47.Ring 45 is held in place by snap ring 48 snapped into the recess 49.Ring 44 may be provided with threaded openings 50 to receive a tool forremoval of the ring from bore 33.

The outer holder recess is shown to contain belting and neoprene packingrings 52 and 53 split in the manner of rings 40 and 41 to be insertiblewithin and removable from the recess. This packing is compressiblelongitudinally of the holder and expansible outwardly against the bodysurface 22, by a ring 55 composed of sections 55a split like the holderand receiving screws 56 having heads 57 accommodated within counterbores58 in the top of the head. Upon rotation of the screws, the ringsections 55a are brought upwardly against the packing, compressing thelatter between the angular ring and holder surfaces 59 and 35 tocompress and expand the packing. The

screws are held in adjusted positions by tubular stop nuts 60 throughwhich a driver may be inserted for adjustment of screws 55.

The bottom holder body recess receives between shoulders 36 and 37 apair of split belting rings 61 which have a scaling function in relationto the body surface 22 and also provide reduced friction support for thepacking assembly upon surface 24. A split neoprene ring 62 is carried onthe top surface of the packing holder 28, and normally, or in theinactive state of the head, is spaced at 63 below a stop surface 64presented by the underside of a retaining ring 66. Referring to FIG. 2,the retaining ring is shown to have at 67 a gap sufficiently wide topermit placement of the ring about the kelly, the ring carryingcircularly spaced lugs 68 which are insertible through openings 681 intogrooves 682 wherein the lugs are rotatable using the ring handles 69 tothe dotted line positions to releasably retain the ring within the body18. Thus the ring serves as a retainer against upward displacement ofthe packing assembly 25 out of the body, and it also serves as a stop tolimit upward displacement of the packing assembly under the influence ofbottom gas pressure during drilling.

In operation, and assuming the packing holder 28 and the associatedsplit packing and other ring parts to be assembled about the kelly andwithin the body 18 according to FIG. 3, rotation of the kelly isimparted to the packing assembly, and the latter is displaced upwardlyby the gas pressure below, so that the non-metallic ring 62 engages androtates against the stop surface 64. In normal operations, the gaspressure exerted upwardly against the assembly will not be of sufiicientmagnitude to create severe wearing condition in the interengagement ofthe ring 62 with surface 64. But in any event, the ring is easilyreplaceable. Lubricated engagement of the outer packing against the bodysurface maintains an effective seal throughout rotation, againstconsequential gas leakage about the assembly 25, while the inner packing39 similarly seals against consequential leakage about the kelly.

Under some circumstances it may be desirable to utilize a drill bit oflarger size than could be passed through a body 18 whose diameter hasbeen determined only from a standpoint of accommodating the internalpacking assembly. Since, for sealing purposes, the diameter of the bodymay advantageously be kept relatively smaller, and it may be morepracticable to stock smaller diameter head assemblies corresponding toFIG. 3, for all uses and drill bit sizes, provision may be madeaccording to FIG. 6, for adapting a standard size drilling head to anouter body sized to afford larger area for tool passage. Here thethreading head body 75 has welded to it upper and lower liner or adapterrings 76 and 77 which are received within an enlarged outer body 78,ring '76 carrying a key 79 engageable against screw 81 to preventrotation of the packing head assembly within the body 78. Upwarddisplacement is prevented by set screw 81, and ring 76 may be providedwith one or more lifting hooks 82 for use in removal of the head andring assembly from the body. The latter contains an annular space 83through which coolant may be circulated from inlet 84- to outlet 85.Ring 77 contains split packing rings 86 which seat against the upper endof the nipple 87. Thus the bodies 75 and 78 remain stationary duringdrilling. Here, lubricant is shown to be fed under constant pressure tothe packing assembly 25' by way of line 88 connecting with passage 89 inthe wall of body 75 and discharging at 90 about the packing assembly inthe manner of line 26 in FIG. 3.

The packing assembly structure corresponds to that previously describedwith reference to FIG. 3, and accordingly, corresponding parts are giventhe same reference numerals.

I claim:

1. A gas drilling head for well casing and adapted to receive apolygonal cross section kelly extent of a drill string through whichpressurized gas is introduced to the well and casing, comprising atubular stationary body including means for attachment to the casing, ametallic tubular diametrically split packing holder within said body andexposed to casing pressure inside the bottom of the body, said holderhaving a polygonal kelly-passing opening extending therethroughcoaxially of the body and having such size that the holder is rotatablydriven by the kelly, packing means carried by the inside and outside ofsaid holder for rotation therewith and having sealing engagement withthe kelly and body wall, said holder and packing being movable up anddown relative to both the body and kelly, stop means carried by the bodyand normally spaced above the holder and packing whereby the holder andpacking are simultaneously rotatable in the body and upwardlydisplaceable therein by the casing gas pressure.

2. A drilling head according to claim 1, in which packing means is ofsubstantially annular form and is split radially of the holder.

3. A drilling head according to claim 2, in which said holder has acentral cavity and an outer surrounding recess containing a portion ofsaid packing means.

4. A drilling head according to claim 3, in which said packing meanscomprise packing layers in substantially annular radially split form.

5. A drilling head according to claim 4, including also means carried bysaid holder and adjustable to press said packing means against the kellyand body wall.

6. A drilling head according to claim 4, in which said stop meanscomprise a ring removably received within the upper interior of the bodyand serving to retain said holder and packing means therein and toarrest upward displacement of the holder.

7. A drilling head according to claim 4, including also means formingstop shoulders in the body above and be low the holder and packing meansat spacing greater than the axial dimension of the holder and packingmeans and operable to limit their up and down displacements.

8. A drilling head according to claim 1, in combination with an outerrelatively large diameter body containing and spaced about the firstmentioned body, and means stationarily supporting said first mentionedbody within the outer body.

9. A drilling head according to claim 8, in which said supporting meanscomprise vertically spaced rings on the outside of said first mentionedbody and engaging the inside of the outer body, and means releasablyretaining the first mentioned body and said rings in the outer body.

10. A gas drilling head for well casing and to receive a polygonal crosssection kelly extent of a drill string through which pressurized gas isintroduced to the well and casing, comprising a tubular stationarycasing head body having an interior to receive casing pressure, and acasing pressure responsive packing device within said body andcomprising a metallic tubular essentially cupshaped diametrically splitpacking holder having a poly onal kelly passing opening and rotatable insaid body by the kelly, first annular packing means carried inside saidholder and having a polygonal kelly passing opening coaxial with thebody, second annular packing means carried at the outside of saidholder, both said packing means being split to be applicable laterallyrespectively about the kellyand holder, the packing being operableduring drilling by rotation of the kelly to pass and seal against thesurfaces of the kelly and also to engage and seal against the insidesurface of the stationary body, said packing device being movable up anddown relative to the body and kelly, stop means carried by the body andnormally spaced above said device, said device being accommodated forvertical floating movement within the body in the respect of beingdisplaceable upwardly against said stop means in response to casingpressures whereby said device is simultaneously rotatable and axiallyshiftable Within the body.

Ill. A drilling head according to claim 10, in which said body containsmeans forming vertically spaced stop surfaces spaced apart above andbelow said device a distance greater than the axial dimension of saiddevice whereby said surfaces are alternately and rotatably engageable bysaid packing device at the extremities of its axial displacement.

12. A drilling head according to claim 10, in which said packing holdercomprises screws interconnecting its diametrically split sections.

13. A drilling head according to claim 10, in which said holder hasmetal-toanetal driven contact with the kelly below said packing means.

14. A drilling head according to claim 10, in which said stop meanscomprises a ring removably received within the upper interior of saidbody and serving to retain the packing device therein.

References Cited by the Examiner UNITED STATES PATENTS 1,727,583 9/1929Cant 2774 1,867,045 7/1932 Young et al. 277-173 2,199,735 4/1940 Beckman2773l 2,243,340 4/1941 Hild 27731 2,578,669 12/1951 Butterfield et al.166-84 2,846,247 8/1958 Davis 16684 CHARLES E. OCONNELL, PrimaryExaminer. I. A. LEPPINK, Assistant Examiner.

1. A GAS DRILLING HEAD FOR WELL CASING AND ADAPTED TO RECEIVE APOLYGONAL CROSS SECTION KELLY EXTENT OF A DRILL STRING THROUGH WHICHPRESSURIZED GAS IS INTRODUCED TO THE WELL AND CASING, COMPRISING ATUBULAR STATIONARY BODY INCLUDING MEANS FOR ATTACHMENT TO THE CASING, AMETALLIC TUBULAR DIAMETRICALLY SPLIT PACKING HOLDER WITHIN SAID BODY ANDEXPOSED TO CASING PRESSURE INSIDE THE BOTTOM OF THE BODY, SAID HOLDERHAVING A POLYGONAL KELLY-PASSING OPENING EXTENDING THERETHROUGHCOAXIALLY OF THE BODY AND HAVING SUCH SIZE THAT THE HOLDER IS ROTATABLYDRIVEN BY THE KELLY, PACKING MEANS CARRIED BY THE INSIDE AND OUTSIDE OFSAID HOLDER FOR ROTATION THEREWITH AND HAVING SEALING ENGAGEMENT WITHTHE KELLY AND BODY WALL, SAID HOLDER AND PACKING BEING MOVABLE UP ANDDOWN RELATIVE TO BOTH THE BODY AND KELLY, STOP MEANS CARRIED BY THE BODYAND NORMALLY SPACED ABOVE THE HOLDER AND PACKING WHEREBY THE HOLDER ANDPACKING ARE SIMULTANEOUSLY ROTATABLE IN THE BODY AND UPWARDLYDISPLACEABLE THEREIN BY THE CASING GAS PRESSURE.